Molecular Phylogeny of Archaea from "non-extreme" Environments

Despite our increasing knowledge of the scale of
microbial diversity, most microbes observed in
natural environments remain uncultivated, their
ecology and functional roles are unknown and our
understanding of the composition of the natural
microbial world is therefore rudimentary. However,
modern molecular methods provide an easy way of
surveying microbial biodiversity using ribosomal RNA
gene sequences retrieved directly from the
environment. The most significant finding from the
application of such new approaches was the discovery
of high numbers of novel archaeal phenotypes. Before,
it was considered that Archaea were restricted to
specialized "extreme" environments characterized by
high temperature, salinity, pH, or strict anoxic.
Over the last decade, a ubiquitous distribution of
"non-extreme" Archaea in a wide variety of temperate
and cold terrestrial and aquatic environments was
demonstrated. The results presented in this thesis
include the discovery of unexpected and new Archaea
in boreal forest soil, freshwater forest lake and
temperate estuarine sediment samples. We suggest that
Archaea are ecologically much more successful and
globally important than previously thought.

Autorentext
Born in Russia, working in Finland since 1993. PhD in microbiology at University of Helsinki. Main research interest focuses on the molecular microbial ecology and phylogeny. Specialized in the study of Archaea from different "non-extreme" environments.

Klappentext
Despite our increasing knowledge of the scale of microbial diversity, most microbes observed in natural environments remain uncultivated, their ecology and functional roles are unknown and our understanding of the composition of the natural microbial world is therefore rudimentary. However, modern molecular methods provide an easy way of surveying microbial biodiversity using ribosomal RNA gene sequences retrieved directly from the environment. The most significant finding from the application of such new approaches was the discovery of high numbers of novel archaeal phenotypes. Before, it was considered that Archaea were restricted to specialized "extreme" environments characterized by high temperature, salinity, pH, or strict anoxic. Over the last decade, a ubiquitous distribution of "non-extreme" Archaea in a wide variety of temperate and cold terrestrial and aquatic environments was demonstrated. The results presented in this thesis include the discovery of unexpected and new Archaea in boreal forest soil, freshwater forest lake and temperate estuarine sediment samples. We suggest that Archaea are ecologically much more successful and globally important than previously thought.